Closure for cylinder lock mechanism

ABSTRACT

A lock cylinder rotatable in a lock body has a cavity in its front, closed by a cap having a key aperture aligned with a keyway in the cylinder. A shutter in the cavity slides to and from a closed position blocking the key aperture, guided by a tongue on its rear received in a groove in the bottom of the cavity. A coiled expansion spring reacting between the cavity wall and the tongue is inclined to the cylinder axis to bias the shutter forward into sealing engagement with the rear surface of the cap as well as laterally towards its closed position.

Rubner 51 Dec. 11, 1973 CLOSURE FOR CYLINDER LOCK MECHANISM [75]Inventor: Hugo G. Rubner, Milwaukee, Wis.

[73] Assignee: Briggs & Stratton Corporation,

Wauwatosa, Wis.

22 Filed: June 12,1972

211 Appl. No.: 262,014

[52] U.S. Cl. 70/455 [51] Int. Cl E05b 17/18 [58] Field of Search70/455, 423, 44 B [56] References Cited UNITED STATES PATENTS 3,077,1012/1963 Jacobi 70/455 2,932,186 4/1960 Mahrley 70/455 1,965,942 7/1934Jacobi 70/455 Primary Examiner-Robert L. Wolfe Attorney-4m Milton Jones[57] ABSTRACT A lock cylinder rotatable in a lock body has a cavity inits front, closed by a cap having a key aperture aligned with a keywayin the cylinder. A shutter in the cavity slides to and from a closedposition blocking the key aperture, guided by a tongue on its rearreceived in a groove in the bottom of the cavity. A coiled expansionspring reacting between the cavity wall and the tongue is inclined tothe cylinder axis to bias the shutter forward into sealing engagementwith the rear surface of the cap as well as laterally towards its closedposition.

7 Claims, 6 Drawing Figures 1 CLOSURE FOR CYLINDER LOCK MECHANISM Thisinvention relates to cylinder locks such as are used for automobiledoors and rear compartment lids, and the invention is more particularlyconcerned with improved closure means for preventing the entry ofmoisture and dirt into the internal mechanism of such a lock through itskey aperture.

The general object of the present invention isto provide an improvedclosure for the key aperture of a cylinder lock; and moreparticularly toprovide improvements in a key aperture closure of the generaltypedisclosed in US. Pat. No. 1,965,942, issued to E. N. Jacobi on July 10,1934, wherein the key aperture is normally closed-by a shutter whichflatwise underliesa cap on the lock cylinder and the shutter is cammedlaterally away from its closed position by the nose of a key beinginserted rearwardly into the cylinder.

In the closure disclosed in that patent the shutter is closelybutslideably confined between a forwardly facing surface on the lockcylinder and a flat rearwardly facing surface of amp that is securedacross the front of the cylinder, and such confinement of the shutter isrelied upon to maintain sealing engagement between the front face of theshutter and the rear surface of the cap. However, it will be apparentthat such sealing engagement will not be maintained after the mechanismhas been actuated often enough to cause slight wear on the slidinglyengaged surfaces, and will not be achieved in the first instance unlessthe mechanism is manufactured to very close tolerances. The shutter ofthe Jacobi patent also had a tendency to become jammed due to cockingthereof and consequent wedging of guide surfaces on its opposite endswith mating surfaces on the cylinder.

With these considerations in mind, it is an important object of thisinvention to provide a closure which is of the general character justdescribed but which, however, isnot dependent upon the maintenance ofclose manufacturing tolerances or the avoidance of wear on slidingsurfaces for maintaining the seal intended to be afforded by itsshutter.

Hence, it is a purpose of this invention to provide a shutter typeclosurefor a cylinder lock mechanism wherein guide surfaces on the backof the shutter, spaced from and of greater length than its oppositeends, are engageable with mating surfaces on the cylinder to assuresmooth sliding motion of the shutter between open and closed positions.

More specifically, it is an object of this invention to provide ashutter type closure for a cylinder lock mechanism, wherein a springthat urges the shutter laterally towards its closed position alsoservesto bias the shutter bodily forwardlyso that when the shutter is inits closedposition it is maintained in good flatwise sealing engagementwith a cap on the front of the cylinder.

Another specific object of this invention is to reduce the cost of lockclosures of the character described by so arranging and organizing theparts thereof as to make it possible for the closure to maintain a goodseal without the necessity for holding unduly close tolerances inmanufacture of the mechanism.

It is alsoa specific object of this invention to provide a shutter typeclosure for a cylinder lock mechanism shutter to its closed position toinsure that the shutter will move bodily forwardly to the extentnecessary to make good sealing engagement with a flat rear surface on acap that is secured to the front of the cylinder.

With these observations and objectives in mind, the manner in which theinvention achieves its purpose will be appreciated from the followingdescription and the accompanying drawing which exemplify the invention.

The accompanying drawing illustrates one complete example of anembodiment of the invention constructed according to the best mode sofar devised for the practical application of the principles thereof, andin which:

FIG. 1 is a front perspective view of a cylinder lock mechanismembodying the principles of this invention;

FIG. 2 is a sectional view of the front portion of the lock mechanism,taken on the plane of the line 2-2 in FIG. 1;

FIG. 3 is a view similar to FIG. 2, but with the key shown received inthe lock cylinder and the shutter being held in its open position by it;

FIG. 3a is a fragmentary sectional view taken through FIG. 1 on theplane of the line 3a:-3a;

FIG. 4 is a sectional view taken on the plane of the line 44 in FIG. 1;and

.FIG. 5 is a sectional view taken on the plane of the lineS-S in FIG. 4.

Referring now more particularly to the accompanying drawings, thenumeral 5 designates generally a lock mechanism embodying the principlesof this invention, comprising, in general, a lock body 6 having a bore 7and a concentric counterbore 8 that opens to its front. Rotatable in thebore is a lock cylinder 9 having at its front an enlarged diameterconcentric head IOthat is received in the counterbore 8.

An axially extending keyway 11 in the cylinder opens to the front end.thereof, to receive a key 12 by which the cylinder can be rotatedbetween defined locked and unlocked positions. As isconventional, thekeyway is slot-like, narrow and deep, that is, elongated in onedimension transverse to the cylinder axis and rather narrow in its otherdimension transverse to said axis. At its front, within its enlargedhead 10, the cylinder has a forwardly opening cavity 13. The shape ofthis cavity is described in detail hereinafter, but at this point itshould be noted that the cavity is in part defined by a generallyforwardly extending surface 14 along one of the longer dimensions of thekeyway, and that the cavity extends laterally from the other side of thekeyway nearly to the edge portion of the: head 10. The cavity is closedby a cap 15 that fits over the front of the cylinder and has a flat rearsurface 16 facing into the cavity.

The cap has in it a key aperture 17 which is axially in line with thekeyway 11 and which is of a shape that corresponds to the shape of thekeyway as viewed from the front end of the cylinder. Normally the keyaperture 17 is closed and sealed by a shutter or closure element 18 thatis disposed in the cavity 13, behind the cap 15. In the closed positionof the shutter a flat front surface thereon is snugly engaged againstthe flat rear surface 16 of the cap, and the shutter extends across thekey aperture to block it, with one edge of the shutter engaged againstthe forwardly extending surface 14 on the cylinder.

As the key is moved rearwardly toward the key aperture 17, its nosetends to engage in a rearwardly inclined depression 19 in the frontsurface of the cap, directly adjacent to the key aperture and at thesame side thereof as the cavity surface 14. The depression 19 in the captranslates rearward thrust on the key into partially lateral motion andguides the key into the key aperture. On the front surface of theshutter, along its edge 20 that engages the cavity surface 14, there isa chamfer or bevel 21 that is rearwardly inclined oppositely to theinclination of the depression 19. The chamfer 21, in cooperation withthe depression, causes the shutter to be cammed away from its closedposition in consequence of rearward inserting movement of the key.

As viewed from the front of the cylinder the shutter 18 is substantiallyT-shaped, with a short stem portion 22 that projects laterally from itsmain body portion at the side of the latter remote from its abovementioned edge 20. The shutter is preferably a die casting, and it has aguide block 23 formed thereon to guide the shutter in its opening andclosing motion. The block 23 is in the nature of a rectangularrearwardly and laterally projecting tongue that is received in a ratherclosely fitting forwardly opening groove 24in the cylinder, at thebottom of the cavity 13.

The block 23 extends lengthwise along the stem portion 22 of the shutterand across the rear of its elongated main body portion, intermediate theends thereof; and the groove 24 in which the block is received extendslaterally away from the keyway at the side thereof opposite the surface14.

It is important to note that the opposite longitudinal sides 23' of theblock provide elongated shutter guide surfaces which are slidinglyengaged with the adjacent sides of the groove 24 in the cylinder so thatthe shutter is guided for translatory movement toward and from itsclosed position, along a path normal to the long dimension of theshutter. These surfaces on the shutter are located so as to be paralleland closely adjacent to a plane which contains the cylinder axis andwhich is crosswise of the main body portion of the shutter, and saidsurfaces are substantially longer than the end surfaces of the shutter.

Not only are the guide surfaces 23 longer than the end surfaces of theshutter, but they are spaced a substantial distance from said endsurfaces. This construction assures against jamming or binding of theshutter by minimizing cocking of the guide block in the cylinder groove24; and is far better than trying to guide shutter movement through theprovision of guide surfaces at its opposite ends where slight tilting ofthe shutter is magnified and can easily result in binding or jamming ofthe shutter.

Attention is directed to the fact that the guide block 23 is formed witha pocket 25 which opens rearwardly and to the outer end of the stemportion 22. The pocket is closed at its end adjacent to the shutter edge20, and it more or less houses the inner end portion of a coiledexpansion spring 26 by which the shutter is urged toward its closedposition. The inner end of the spring bears against a surface 27 at theclosed end of the pocket 25, and its outer end bears against an opposingsurface 28 on the cylinder at the radially outer end of the cylindergroove 24.

An important feature of the invention resides in the fact that thespring 26 is so oriented that its axis is inclined forwardly andradially inwardly relative to the cylinder axis, so that the spring notonly serves to bias the shutter laterally towards its closed positionbut also urges it forwardly into firm sealing engagement with the flatrear surface of the cap. To insure that the spring will have suchoblique orientation, the end surface 27 in the pocket 25, which providesone seat for the spring, and the surface 28 on the cylinder thatprovides the other spring seat, are correspondingly inclined.Furthermore, the groove 24 in the cylinder is formed with a forwardlyopening well 30 in its bottom surface that is tapered to partiallyreceive end coils of the spring and accommodate their obliqueorientation.

If desired, pilots which project into the opposite ends of the springcan be provided by small teats 31 and 32, formed on the shutter andcylinder respectively.

Because the guiding surfaces 23' on the block are elongated and spacedinwardly from the ends of the shutter, and since the axis of the springis aligned with the center line of the shutter guide means thatcomprises the tongue or block 23 and the groove 24, and is also alignedwith the center of the lateral thrust force that the key exerts againstthe shutter, there is no occasion for the shutter to be cocked or cantedas it slides toward and from its closed position, and it does so with asmooth, easy action.

In cooperation with the oblique orientation of the spring, good sealingclosure of the shutter is further insured by reason of the fact that thecylinder head has a surface 14 at the entrance to the key slot whichdiverges forwardly and radially outwardly, away from the surface 14, atan acute angle to the cylinder axis, as best seen in FIG. 3a; and theedge 20 of the shutter that engages said surface 14 is formed withcorrespondingly inclined surfaces 20. Hence, in the last stages ofmotion of the shutter to its fully closed position under the biasingforce of the spring, these surfaces 14 and 20' cammingly engage oneanother to propel the shutter forwardly into snug engagement with therear surface of the cap.

Those skilled in the art will appreciate that merely sealing theentrance to the key aperture 17 against the ingress of dirt and moistureis not in itself sufficient to insure against the entry of foreginmatter into the interior of the lock mechanism. There is necessarilysome clearance between the cylinder and the lock body, and it isessential that foreign matter be prevented from entering the lockmechanism through the clearance space. To that end the lock body isprovided with an annular bezel 33 which can be clinched over a largediameter head portion 35 on its front. The radially inner portion ofthis bezel has a flat rearwardly facing circumferential surface that issnugly engaged by a flat, circumferential, radially outermost surface onthe cap 15. As illustrated in FIG. 2, the cap has a concentric enlargeddiameter portion behind the bezel to provide the forwardly facingsurface that engages the bezel, and its smaller diameter front portionprojects forwardly through the bezel.

To maintain a good seal between the bezel and the cap, a wave washer 37is confined between the rearwardly facing shoulder on the enlarged head10 on the cylinder and the opposing circumferential shoulder surfacedefined by the junction of the bore 7 and counterbore 8 in the body. Thewave washer of course biases the cylinder forwardly in the lock body.

From the foregoing description taken with the accompanying drawings itwill be apparent that this invention provides closure means for acylinder lock mechanism of the type used on automobile doors, rear decklids and the like, which closure means provides good assurance againstentry of dirt and moisture into the lock mechanism without requiringmaintenance of unduly close manufacturing tolerances, is substantiallyunaffected by ordinary wear, and features a smoothworking key actuatedshutter for normally sealing the key aperture of the lock.

Those skilled in the art will appreciate that the invention can beembodied in forms other than as herein disclosed for purposes ofillustration.

The invention is defined by the following claims:

1. A lock mechanism comprising a rotatable cylinder in which there is akeyway that opens to the front of the cylinder, said cylinder alsohaving a forwardly opening cavity in its front, at one side of thekeyway, a cap over the front of the cylinder closing the cavity exceptfor a key receiving aperture in the cap that is aligned with the keyway,and a shutter in the cavity behind the cap, normally in closed positionsealing the key aperture but movable laterally, in response to therearward thrust of a key inserted into the key aperture, to an openposition permitting the key to enter the keyway, said lock mechanismbeing characterized by:

A. the cap having a flat rear surface;

B. the shutter having a flat front surface slidingly and sealinglyengageable with said front rear surface on the cap;

C. a tongue-like guide portion on the rear of the shutter, intermediatethe ends thereof, and extending a substantial distance laterally to saidone side of the keyway;

D. the cylinder having in its cavity a forwardly opening groove thatextends to said one side of the keyway and in which the guide portion isguidingly received to constrain the shutter to substantially translatorymotion toward and from its closed position;

E. a coiled compression spring in said groove, reacting between said endthereof and said guide portion on the shutter; and

F. cooperating means on the shutter and on the cylinder, in said cavity,engaging end portions of the spring to maintain it with its axisoriented obliquely to the cylinder axis so that the spring urges theshutter forwardly toward flatwise sealing engagement of its frontsurface with the rear surface of the cap as well as laterally toward itsclosed position.

2. The lock mechanism of claim 1, further characterized by:

G. said shutter being substantially T-shaped as viewed from the front ofthe cylinder;

H. said tongue-like guide portion extending along the stem of the T andsubstantially entirely across the shutter to afford guidance to theshutter in its movement to and from its closed position; and

. said guide portion having a groove therein which opens rearwardly andto said end of the forwardly opening groove in the cylinder, and inwhich said spring is received, said groove in the guide portion of theshutter beingclosed at one end to provide a seat for the spring.

3. The lock mechanism of claim 2, further characterized by:

J. the closure member having a teat projecting into said groove thereinthat serves as a pilot for an end portion of the spring.

4. The lock mechanism of claim 1, further characterized by:

another and with the spring to maintain the shutter' in firm flatwisesealing engagement with the cap.

5. The lock mechanism of claim ll wherein the cylinv der is rotatable ina lock body that has a bore and a forwardly opening counterbore, andwherein the cylinder has an enlarged head that is received in saidcounterbore, further characterized by:

M. an annular bezel on the lock body having a radially innercircumferential surface that flatwise overlies a radially outerforwardly facing circumferential surface on said cap; and

N. a wave washer confined between a forwardly fac ing shoulder in thelock body, defined by the junction of said bore and counterbore, and arearwardly facing circumferential shoulder on the cylinder, defined bysaid enlarged head thereon, to bias the cylinder forwardly in the lockbody and thus maintain sealing engagement between the cap and the bezel.

6. in a lock mechanism of the type having a rotatable cylinder with acap on its front, a keyway therein opening forwardly through an aperturein the cap, and a shutter under the cap, at one side of the keyway,movable along a path crosswise of the cylinder axis toward and from anoperative position closing the entrance to the keyway, the improvementwhich comprises:

A. said shutter having a body portion which is elongated in a directionsubstantially normal to the path of shutter motion and to the cylinderaxis, and hav ing a surface at its front shaped to having matingengagement with the rear surface of the cap;

B. means on the rear of the shutter defining a block which is spacedfrom both ends of the shutter and which extends a substantial distancelaterally from the body thereof in a direction away from the key way,said block being hollow so as to define a pocket which opens rearwardlyaway from the shutter and laterally away from the keyway;

C. the cylinder having a cavity in its front to accommodate the shutter,and a groove in the bottom of the cavity to accommodate said block onthe rear of the shutter;

D. means defining said path of shutter motion, comprising elongatedsurfaces on each side of said block which are contiguous to andcooperate with similar surfaces on the sides of said groove, and othersurfaces on the back of the block which are contiguous to the bottom ofsaid groove;

E. a spring disposed partly in said pocket and acting upon the shutterto yieldingly urge it laterally toward the keyway to its operativeposition;

F. and means connecting the spring with a front portion of the cylinderand with said block on the rear of the shutter to hold the spring in anattitude such that it exerts force on the shutter urging it forwardlyinto sealing engagement of said front surface thereof with said rearsurface of the cap.

7. The lock mechanism of claim 6, further characterized by a cam surfaceon that portion of the shutter which is adjacent to the keyway, and amating cam surface on the cylinder adjacent to that side of the keywaywhich opposes the shutter,

said cam surfaces being cooperable with the spring to force the shuttertightly against the rear surface of the cap in consequence of movementof the shutter to its operative position.

} UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3 2 DatedDecember 11, 1973 Inventor(s) Hugo n r It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

Columnlk line HO, "foregin" should read foreign-- Column 5 line 25(claim 1, para B, line 2 "front" should read T--flat-- Signed and sealedthis 9th day of April 19714. 7

(SEAL) Attestz EDWARD I LFLETGHERJR. C. MARSHALL DANN Atte sting OfficerCommissioner of Patents FORM PC4050 uscoMM-oc man-P09 U.S, GOVERNMENTPRINTING OFiFlCE l9, O-Jl-334,

1. A lock mechanism comprising a rotatable cylinder in which there is akeyway that opens to the front of the cylinder, said cylinder alsohaving a forwardly opening cavity in its front, at one side of thekeyway, a cap over the front of the cylinder closing the cavity exceptfor a key receiving aperture in the cap that is aligned with the keyway,and a shutter in the cavity behind the cap, normally in closed positionsealing the key aperture but movable laterally, in response to therearward thrust of a key inserted into the key aperture, to an openposition peRmitting the key to enter the keyway, said lock mechanismbeing characterized by: A. the cap having a flat rear surface; B. theshutter having a flat front surface slidingly and sealingly engageablewith said front rear surface on the cap; C. a tongue-like guide portionon the rear of the shutter, intermediate the ends thereof, and extendinga substantial distance laterally to said one side of the keyway; D. thecylinder having in its cavity a forwardly opening groove that extends tosaid one side of the keyway and in which the guide portion is guidinglyreceived to constrain the shutter to substantially translatory motiontoward and from its closed position; E. a coiled compression spring insaid groove, reacting between said end thereof and said guide portion onthe shutter; and F. cooperating means on the shutter and on thecylinder, in said cavity, engaging end portions of the spring tomaintain it with its axis oriented obliquely to the cylinder axis sothat the spring urges the shutter forwardly toward flatwise sealingengagement of its front surface with the rear surface of the cap as wellas laterally toward its closed position.
 2. The lock mechanism of claim1, further characterized by: G. said shutter being substantiallyT-shaped as viewed from the front of the cylinder; H. said tongue-likeguide portion extending along the stem of the T and substantiallyentirely across the shutter to afford guidance to the shutter in itsmovement to and from its closed position; and I. said guide portionhaving a groove therein which opens rearwardly and to said end of theforwardly opening groove in the cylinder, and in which said spring isreceived, said groove in the guide portion of the shutter being closedat one end to provide a seat for the spring.
 3. The lock mechanism ofclaim 2, further characterized by: J. the closure member having a teatprojecting into said groove therein that serves as a pilot for an endportion of the spring.
 4. The lock mechanism of claim 1, furthercharacterized by: K. the cylinder having, at the opposite side of thekeyway and extending along the longer dimension thereof, a surface thatdiverges forwardly and radially outwardly from the cylinder axis; and L.the shutter having a mating inclined surface engageable with saidinclined surface on the cylinder upon movement of the shutter to itsclosed position, said inclined surfaces cooperating with one another andwith the spring to maintain the shutter in firm flatwise sealingengagement with the cap.
 5. The lock mechanism of claim 1 wherein thecylinder is rotatable in a lock body that has a bore and a forwardlyopening counterbore, and wherein the cylinder has an enlarged head thatis received in said counterbore, further characterized by: M. an annularbezel on the lock body having a radially inner circumferential surfacethat flatwise overlies a radially outer forwardly facing circumferentialsurface on said cap; and N. a wave washer confined between a forwardlyfacing shoulder in the lock body, defined by the junction of said boreand counterbore, and a rearwardly facing circumferential shoulder on thecylinder, defined by said enlarged head thereon, to bias the cylinderforwardly in the lock body and thus maintain sealing engagement betweenthe cap and the bezel.
 6. In a lock mechanism of the type having arotatable cylinder with a cap on its front, a keyway therein openingforwardly through an aperture in the cap, and a shutter under the cap,at one side of the keyway, movable along a path crosswise of thecylinder axis toward and from an operative position closing the entranceto the keyway, the improvement which comprises: A. said shutter having abody portion which is elongated in a direction substantially normal tothe path of shutter motion and to the cylinder axis, and having asurface at its front shaped to having mating engagement with the rearsUrface of the cap; B. means on the rear of the shutter defining a blockwhich is spaced from both ends of the shutter and which extends asubstantial distance laterally from the body thereof in a direction awayfrom the keyway, said block being hollow so as to define a pocket whichopens rearwardly away from the shutter and laterally away from thekeyway; C. the cylinder having a cavity in its front to accommodate theshutter, and a groove in the bottom of the cavity to accommodate saidblock on the rear of the shutter; D. means defining said path of shuttermotion, comprising elongated surfaces on each side of said block whichare contiguous to and cooperate with similar surfaces on the sides ofsaid groove, and other surfaces on the back of the block which arecontiguous to the bottom of said groove; E. a spring disposed partly insaid pocket and acting upon the shutter to yieldingly urge it laterallytoward the keyway to its operative position; F. and means connecting thespring with a front portion of the cylinder and with said block on therear of the shutter to hold the spring in an attitude such that itexerts force on the shutter urging it forwardly into sealing engagementof said front surface thereof with said rear surface of the cap.
 7. Thelock mechanism of claim 6, further characterized by a cam surface onthat portion of the shutter which is adjacent to the keyway, and amating cam surface on the cylinder adjacent to that side of the keywaywhich opposes the shutter, said cam surfaces being cooperable with thespring to force the shutter tightly against the rear surface of the capin consequence of movement of the shutter to its operative position.